LONDON (Reuters) - Ratings agency Standard & Poor's said on Monday that signs of a post-Brexit vote recovery in Britain's economy may prove to be a "mirage" as uncertainty about the country's relationship with the European Union weighs on business investment.

"While the news is encouraging, we believe it has no bearing on the cloudy longer-term outlook for the UK economy," Sophie Tahiri, an economist at S&P Global Ratings, said in a report.

British consumers have shown little sign of being hurt immediately by the June 23 referendum decision to leave the EU. Companies reported a slump in business in July before a bounceback in August.

(Reporting by William Schomberg, editing by David Milliken)